Hemlock Woolly Adelgid. A New Treatment.

Hemlock Woolly Adelgid is an invasive pest that sucks the life out of Hemlock trees. Hemlock Woolly Adelgid has always been difficult to treat with Horticultural Oil on trees that are very tall or inaccessible to spray equipment.
A simple basal trunk application of Imidacloprid is as effective as soil injection for controlling Hemlock Woolly Adelgid. The treatment still has the 5-7 year control window as with soil injection, but is much easier to apply. Dragging hoses into the woods is now history. One can now treat many trees with one fill of a backpack sprayer. In addition to being cheaper and easier to apply, this new method allows trees that were previously out of range to now be saved. The treatment is best applied in the Spring or Fall while the trees are more actively transpiring. As with any application method it is very important to get the rate right, too low and it will not be effective too high and it will kill predators of other Hemlock pests such as Elongate Hemlock Scale.
It is now possible to treat so many trees in a short time that the only hold back to saving acres of Hemlocks is the maximum amount of Imidacloprid allowed per acre per year.
I don’t hold out much hope for changing this because so many fools misuse this chemical in ways that have poisoned bees, but would like to see no amount restrictions on its use for this method of application, and only for invasive pests. I don’t even care if Imidacloprid is banned for all other applications, but it is invaluable for controlling Hemlock Woolly Adelgid. With the basal trunk application it is extremely unlikely that, if used carefully, a single bee will be harmed.

By the way. Although Imidacloprid is poisonous to bees, and should always be used with respect to this problem, it has almost certainly been proven through scientific research as not responsible for Colony Collapse Disorder.

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